PRIGEN (PRImate GENes) is a database of chimpanzee (Pan troglodytes verus) cDNAs. The cDNA sequences were derived from full-length cDNA (FLcDNA) libraries of various tissues using the oligo-capping method. We first sequenced 5'-ends of randomly selected clones from the libraries and then started full-length sequencing. The sequences were annotated using similarity searches against NCBI human RefSeq transcripts. PRIGEN currently provides keyword and BLAST searches against 14,004 5'-end cDNA (5'-EST) sequences.